Can someon who did use weed thc test be positive by kissing someone who has smoked weed ? and can a hair drug thc test be positive when you didnt use weed ?

If you do weed the test can be positive if you kiss another weed user or not, although a non-user would not test positive just from kissing a weed user. The hair test detects drug incorporated in the hair during its growth period as derived from the blood. It doesn't get in hair that is properly washed by being around a weed smoker.

You would not test positive by kissing a user. However, if you are exposed the smoke from the user, you may test positive.